12 June 2007

The European Particle Measurement Programme (PMP) has published “Light-duty Inter-laboratory Correlation Exercise (ILCE_LD) Final Report”, authored by Jon Andersson and co-authors, which summarizes the results and findings from Phase 3 of the study.

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The PMP program, conducted under the auspices of the UNECE WP29/GRPE group, was started in 2001 to develop and recommend PM measurement methods to be used for EU type approval testing and development of future emission standards for light- and heavy-duty vehicles. In its Phase 1 and 2, the program recommended two systems:

  • For PM mass measurement, a modified filter method similar to that currently used in Europe, but incorporating changes broadly based on the US 2007 emission certification testing procedure.
  • For particle number measurement, a new method using a condensation particle counter (CPC), a selected size range (23 nm - 2.5 µm), and sample pre-conditioning at 300°C in an evaporation tube. The procedure has been designed to count solid particles only, and to eliminate volatile particles.

The Light Duty Inter-Laboratory Correlation Exercise has conducted testing at 9 test laboratories in the EU, Korea and Japan in order to demonstrate the repeatability and reproducibility of the PMP methods. The exercise involved testing 16 light-duty vehicles including 6 diesels equipped with wall-flow diesel particulate filters (DPFs), 6 conventional diesel vehicles, 3 direct injection (DI) gasoline vehicles and one conventional, multi-point injection gasoline vehicle. A Golden Vehicle—DPF equipped Peugeot 407—was tested at all participating laboratories to allow the inter-laboratory reproducibility of measurements to be assessed. Vehicles were tested over multiple repeats of the NEDC transient test cycle. Measurements of solid particle number emissions, particulate mass and regulated gaseous emissions were taken over each test. In addition to particle number measurements made with a Golden System circulated between laboratories (Matter Engineering rotating diluter, evaporation tube and ejector diluter plus a TSI Condensation Particle Counter), particle number measurements were made with several alternative systems to compare the performance of different measurement systems.

The PMP measurement methods for both PM mass and numbers have been included in the recently adopted Euro 5/6 emission legislation. For passenger cars, the mass based Euro 5/6 PM limit is 3 mg/km, and the number based limit is 5×1011 particles/km.